1. Field of the Invention
The present invention relates, in general, to alarm systems for boats, vending machines, and the like for producing a sustained alarm upon the occurrence of a monitored event such as the unauthorized tampering with of a monitored boat, vending machine, or the like.
2. Background of the Invention
Various alarm systems have been developed for buildings, homes, automobiles, and the like. Most prior art alarm systems, once set off by an unauthorized opening of a door, window, or the like, will typically sound and/or flash an alarm signal until the system is reset by an authorized person even if the door, window or the like is closed. While such operations are desirable with respect to houses and buildings having a continuous source of electrical energy (i.e., the typical 120 volt electrical current supplied to the building or house by a public utility or the like), problems occur when the system is dependent upon a finite source of electrical energy such as a 12 volt direct current automobile battery, in which case the alarm may completely drain the battery before an authorized person can reset the system. This is especially true where the system is used to protect items which may be located remote from authorized persons such as boats moored a distance away from houses, vending machines, etc., or which may be located in fairly loud ambient conditions such as a boat being pulled on a trailer behind an automobile or the like wherein the alarm may be accidentally set off by the movement of the boat and the battery may be completely drained by the time the accident is noticed.
McGahee, U.S. Pat. No. 3,959,789, discloses a check or credit card monitor consisting of a plurality of normally closed switches adapted to be held open by insertion of credit cards or similar items between the switch contacts. The contacts are connected parallel to a timing means adapted to energize a sensory alarm such as an audio signal, vibrator or light a predetermined time after closure of any one of the plurality of switches.
Alexander, U.S. Pat. No. 3,965,465, discloses a switch adapted to fit into a conventional switch box to activate an entryway light of a building for a predetermined period of time after a person has merely touched a door knob or the like. The switch is connected to a conductive latch in a door controlling access to the entryway to receive the minute electrical charge carried by a person attempting to operate the latch through a door knob or the like. Upon being triggered by such a charge, the switch will turn on the light for a predetermined time to provide a convenience for those authorized to enter, and a deterrent for those who are not.
Nobile, U.S. Pat. No. 4,006,451, discloses an alarm circuit module for automobile, home, or industry. The alarm circuit module includes a thermostatic relay, one or more sensor switches attached to doors, windows, etc., a battery or other source of electrical power, and an alarm (i.e., the existing horn of an automobile) for producing an alarm signal when electrically coupled to the battery. When one of the sensor switches is closed by an unauthorized entry through a door or window, etc., an electric circuit will be completed between the battery and the thermostatic relay. After a period of time, the thermostatic relay will heat sufficiently to close an electric circuit between the battery and the alarm to produce an alarm signal continuously for as long as the sensor switch is closed (i.e., as long as the sensor switch is closed, electric current will pass from the battery to the thermostatic relay and keep the thermostatic relay in a heated, closed state), and will cause the alarm to continue producing the alarm signal for a period of time after the sensor switch is reopened.
Rasmussen et al., U.S. Pat. No. 4,125,826, discloses an alarm system utilizing a vehicle transmitter of pulsed ultrasonic energy directed to a stationary receiver outside the vehicle and which renders an alarm if the receiver does not receive ultrasonic energy of a given frequency for a preset time period. The vehicle transmitter is disabled in response to an intruder alarm in the vehicle detecting the presence of an intruder. The receiver alarm is thus activated either by the presence of an intruder or by the vehicle being moved more than a certain distance from the receiver.
Speer, U.S. Pat. No. 4,222,032, discloses a vehicle cover alarm that includes one or more permanent magnets for being attached to an automobile cover or the like, one or more normally open reed switches for being attached to the automobile in locations for being closed or opened by the magnets when the cover is properly placed over the automobile, and an alarm circuit connected to the switches to activate a warning device such as the automobile's horn or a disabling device such as means for cutting off the power to the automobile's fuel pump if the cover is removed from the automobile.
None of the known prior art alarm systems disclose or suggest the present invention. More specifically, none of the known prior art alarm systems disclose or suggest an alarm system including an electrical energy source; alarm means for producing an alarm signal when electrically coupled to the electrical energy source; switch means for movement from a first position to a second position upon the occurrence of a monitored event; and timing means for being activated when the switch means is moved from the first position to the second position and for electrically coupling the alarm means to the electrical energy source the timing means including means for continuing to electrically couple the alarm means to the source of electrical energy for a set period of time even if the switch means is subsequently moved back to the first position during the set period of time; the timing means including means for deactivating the alarm means a certain period of time after the alarm means is activated and for reactivating the alarm means a certain period of time after the alarm means is deactivated if the switch means remains in the second position.